Pb with my BDB: openldap don't start

Hi,
I have this following problem with my openldap server:
bdb_db_open: database already in use
backend_startup_one: bi_db_open failed! (-1)
slapd shutdown: initiated
==> unique_close
slapd destroy: freeing system resources.
slapd stopped.
connections_destroy: nothing to destroy.
is some one can help me ?